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1   /* Copyright 2004 Acegi Technology Pty Limited
2    *
3    * Licensed under the Apache License, Version 2.0 (the "License");
4    * you may not use this file except in compliance with the License.
5    * You may obtain a copy of the License at
6    *
7    *     http://www.apache.org/licenses/LICENSE-2.0
8    *
9    * Unless required by applicable law or agreed to in writing, software
10   * distributed under the License is distributed on an "AS IS" BASIS,
11   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12   * See the License for the specific language governing permissions and
13   * limitations under the License.
14   */
15  
16  package org.acegisecurity.acl.basic.cache;
17  
18  import org.acegisecurity.acl.basic.AclObjectIdentity;
19  import org.acegisecurity.acl.basic.BasicAclEntry;
20  import org.acegisecurity.acl.basic.BasicAclEntryCache;
21  
22  import net.sf.ehcache.Cache;
23  import net.sf.ehcache.CacheException;
24  import net.sf.ehcache.Element;
25  
26  import org.apache.commons.logging.Log;
27  import org.apache.commons.logging.LogFactory;
28  
29  import org.springframework.beans.factory.InitializingBean;
30  
31  import org.springframework.dao.DataRetrievalFailureException;
32  import org.springframework.util.Assert;
33  
34  
35  /***
36   * Caches <code>BasicAclEntry</code>s using a Spring IoC defined <A
37   * HREF="http://ehcache.sourceforge.net">EHCACHE</a>.
38   *
39   * @author Ben Alex
40   * @version $Id: EhCacheBasedAclEntryCache.java,v 1.5 2005/11/17 00:56:47 benalex Exp $
41   */
42  public class EhCacheBasedAclEntryCache implements BasicAclEntryCache,
43      InitializingBean {
44      //~ Static fields/initializers =============================================
45  
46      private static final Log logger = LogFactory.getLog(EhCacheBasedAclEntryCache.class);
47  
48      //~ Instance fields ========================================================
49  
50      private Cache cache;
51  
52      //~ Methods ================================================================
53  
54      public void setCache(Cache cache) {
55          this.cache = cache;
56      }
57  
58      public Cache getCache() {
59          return cache;
60      }
61  
62      public BasicAclEntry[] getEntriesFromCache(
63          AclObjectIdentity aclObjectIdentity) {
64          Element element = null;
65  
66          try {
67              element = cache.get(aclObjectIdentity);
68          } catch (CacheException cacheException) {
69              throw new DataRetrievalFailureException("Cache failure: "
70                  + cacheException.getMessage());
71          }
72  
73          // Return null if cache element has expired or not found
74          if (element == null) {
75              if (logger.isDebugEnabled()) {
76                  logger.debug("Cache miss: " + aclObjectIdentity);
77              }
78  
79              return null;
80          }
81  
82          if (logger.isDebugEnabled()) {
83              logger.debug("Cache hit: " + (element != null) + "; object: "
84                  + aclObjectIdentity);
85          }
86  
87          BasicAclEntryHolder holder = (BasicAclEntryHolder) element.getValue();
88  
89          return holder.getBasicAclEntries();
90      }
91  
92      public void afterPropertiesSet() throws Exception {
93          Assert.notNull(cache, "cache mandatory");
94      }
95  
96      public void putEntriesInCache(BasicAclEntry[] basicAclEntry) {
97          BasicAclEntryHolder holder = new BasicAclEntryHolder(basicAclEntry);
98          Element element = new Element(basicAclEntry[0].getAclObjectIdentity(),
99                  holder);
100 
101         if (logger.isDebugEnabled()) {
102             logger.debug("Cache put: " + element.getKey());
103         }
104 
105         cache.put(element);
106     }
107 }